Family Matters
by Trinity Everett
Summary: "Rick, this is Kate Beckett, my colleague. Beckett, this is Rick Castle, my cousin. I think you'll get along famously." - Beckett learns a little more about both her coworker and her shadow all in the same day. AU, Caskett.


**Family Matters**

 **A Season 1 AU, set after 1x05, but prior to 1x07**

 _This is a late birthday fic for the Prompt Overlord herself. I hope you like this, Lou! Happy Late Birthday!_

* * *

"You've got to be kidding me."

They're messing with her; they must be messing with her. There is _no_ way that this is not some elaborate, bullshit prank Castle has concocted.

Kevin Ryan cannot be related to Rick Castle. There's no way. Absolutely _no_ freaking way. How could her friend – her sweet, easy-going friend – be in any way related to the most asinine, egotistical, annoying man she's ever met in her life?

Both men turn to her, and her stomach drops like a stone. How had she not noticed the resemblance in their eyes?

"Nope," Ryan insists, his glee breaking through the mantra in her head, the steady chant that it is all one big joke on Castle's part. One big 'gotcha' to drive her crazy. Just like when he'd shown up at her precinct with that smug grin and an invitation to stay from the mayor. "His mom is my mother's oldest sister."

"Don't let Mother ever hear you say the 'o' word," Castle jumps in, snickering. "The ensuing meltdown _will_ result in her coming to live with you because she's driven me crazy."

Ryan laughs, holding up a hand in surrender. "I didn't say _old_ , I just said oldest," he adds, turning back to Beckett. "I thought you knew that, Beckett. I'd been telling you about my cousin for ages before Castle joined the team."

Heat floods her cheeks; he just _had_ to say that in front of Castle, didn't he? That's what her shadow needs, more ammunition to use as he tries to charm his way into her life. "You've told us about your family," she snaps, "but you weren't exactly specific that your cousin was _this_ guy when you were doing the talking."

Her fellow detective huhs softly, lifting a shoulder. "Well in that case, I know it's a little bit late, but allow me to formally introduce you. Rick, this is Kate Beckett, my colleague. Beckett, this is Rick Castle, my cousin. I think you'll get along famously," he adds with a snarky little lilt to his voice that has her eyes narrowing. Both he and Esposito have been privy to her feelings about Richard Castle hanging around; he knows how his cousin drives her insane, and he's relishing in that knowledge right now.

His freaking cousin. Jeez. Richard Castle is Kevin Ryan's _cousin_.

"Yes, well, you think lots of things, Ryan. Now I'm going to go back to my paperwork. You guys keep talking about… whatever it is you talk about."

She spins on her heel, making a hasty retreat to the opposite end of the bullpen. Of course, her dismissal doesn't stop Castle from practically tripping his way to her desk with all the grace of an excited basset hound.

"Small world, huh? I didn't even put it together that you were the one Kevin talked about until after I'd already called the mayor about shadowing you."

Yeah, right. She doesn't believe that for a second. There aren't that many female detectives on the squad.

"But just so you know, he has had nothing but amazing things to say about you since he's been in Homicide," Castle adds.

Her jaw shifts. She knows Ryan respects her, both as a detective and as a person, but it is nice to hear that. Not that she's going to admit that, or return the compliment. She has heard good things about her writer shadow – albeit she didn't know the accolades were about him at the time – but thus far she hasn't seen any evidence to back them up.

"Martha's youngest sister?" she asks instead, lifting an eyebrow. "I didn't even know she had a sister."

Castle nods, settling into that god-awful chair he has appropriated as his and placed beside her desk last week. He looks at home here, which only serves to annoy her more.

"Mother actually has three sisters," he says, tapping her desk. "Two brothers, too."

Her brow furrows. Having seen him with his mother and daughter, she wouldn't have expected that; they don't exactly give off the 'Sunday dinners with a large extended family' vibe.

"Pretty big family," she remarks, half-prompting for more.

He lifts a shoulder. "Post-war baby boom. Mother's parents were… less than supportive when she got pregnant with me, especially when she said she wouldn't be quitting acting to get 'a respectable job' to support us, and most of her siblings followed their lead. Suffice to say, we didn't see them very often when I was growing up. We still don't, really."

Kate frowns. He's being oblique with his language, blithe almost, but she knows enough to get what he means; his mother's family cut her off, cut her out of their lives, abandoned them both.

"My aunt – Ryan's mom – got back in contact when she married Kevin's dad. I was seven when Ryan was born, but we still spent a fair amount of time together when I wasn't traveling for Mother's productions or away at boarding school."

Beckett nods, trying to imagine that, a younger Castle playing with a pint-sized version of her teammate. She can't quite manage to picture it, though.

Castle clears his throat. "Anyway, I can assure you, Detective. It's no joke. I have more than one album of embarrassing photographs to prove it."

"Of you or of Ryan?" she asks, her eyes darting across the bullpen to where the rest of her team sits. The boys make a show of looking away, going back to work instead of spying on her and Castle.

"Both?" he says. His eyebrows wiggle, irises sparkle with mirth. "You're welcome to come to my place and see for yourself. Maybe take some more embarrassing pictures of me – or sexy pictures, if you're feeling inclined. I'm open to all possibilities."

She snorts. There's the Castle she knows and cannot stand. "I think I can find enough of those on the internet, Castle. Thanks, but no."

He tuts, but sits back in the chair with his usual airy nonchalance. "Suit yourself. But you're missing out on seeing Ryan's mullet in its prime."

"He did _not_ have a mullet."

Her shadow nods, gleeful once more. "Oh, he did. He was twelve, I think? But since you're not interested…"

She is not going to fall for this, she isn't. It's an obvious attempt to get her to his place, and she is not going to give him the satisfaction of even considering–

"If you come over, I'll throw in the story about Kev's first grade Christmas pageant…" he singsongs. "It's the perfect story to get the revenge I can tell you're plotting."

Damn it. That is just too good to pass up.

"Fine," she agrees, watching his eyes flare wide with triumph. "But you try anything funny, Castle, and you won't have to worry about that waiver you signed with the NYPD."

His grin is teasing, but he just offers her a firm nod and a smile. "Understood, Detective."

He bounds to his feet a little while later, claiming he's going to get a head start on his writing, but she knows better when he turns and asks what she'd like to eat.

"Castle," she snaps, her eyes darting around the room to make sure nobody else has heard any of this conversation. The last thing she needs is to have the entire precinct buzzing about her planning a dinner date with her writer shadow. "I'm coming over to hear embarrassing things about Ryan, not–"

He waves her off, already scooting to the elevator. "I'll figure something out and surprise you. You'll love it."

She is one hundred million percent sure she won't.

* * *

Alexis opens the door before Kate's fist lowers to her side. The girl doesn't seem surprised to see her, but she does give Beckett a shy smile anyway.

"Detective Beckett," Castle's daughter says, stepping aside to grant her entry. "Come in. Dad's in his office, but he said to let you in when you knocked."

Beckett nods, trying not to look as awed stepping into Rick Castle's home as she had just a couple of weeks ago. So he's rich and his place is gorgeous; she's not here to admire his decorating or contemplate for probably the millionth time why he would possibly need to hang around the police station – her – for research, especially now that she knows he's related to a cop.

"You can join him," Alexis adds, closing the door behind her. "I'm just going to grab a drink and go upstairs."

Kate sputters. "Oh, no, you don't have to leave. This isn't for the precinct."

Alexis grins. "I know. But I don't want to intrude when you're–"

"It's not a date either," she insists quickly. "I'm, it's – your dad offered to show me – I found out that Detective Ryan is your dad's cousin, so your dad offered to show me some old pictures of Ryan so I can give him a hard time at work."

Which doesn't really sound like this _isn't_ an unconventional date, now that she says it aloud, but Alexis is polite enough not to call her on that. Instead the girl just nods, rounding the kitchen counter to grab a glass out of the cabinet.

"Would you like anything, Detective?" she asks, glancing over her shoulder. "We have water and some soda, and Dad has beer and more wine than I can describe."

"Oh no, I'm fine, thank you."

Alexis nods, busying herself with moving to the fridge and filling her glass with ice. "Can I take your coat at least?"

Beckett glances down, feeling her cheeks heat at the realization that she is, in fact, still wearing her coat. "Ah, I'll, I got it. Hang it up or drape it?"

The girl shrugs. "It's up to you. The closet is on the right if you want to hang it, though."

Kate nods, retracing her steps to the front closet. She wiggles out of her coat, draping it over a hanger and sliding it beside a worn leather jacket she can only assume belongs to Castle.

"Wait, you just found out that Kevin and Dad are cousins?" Alexis asks, grabbing a box of cereal from the pantry. "I thought you knew when Dad started shadowing you."

Beckett's cheeks flame. Some detective she is. She saw how easily Castle had integrated himself into the precinct, how readily the guys had accepted him, and she'd assumed it was just to annoy her. Now she knows better.

"Ah, no. No, I found out recently. Today recently."

Alexis grins. "That's so weird. Well, it's not that long, I guess," she amends quickly, as if she worries she's offended Kate. "It's only been a month or so. And if it makes you feel any better, Dad looked pretty stunned when he realized that you were the one Kevin had talked about, too."

Strangely enough, it does help, knowing that it wasn't just bullshit Castle was spouting earlier to keep her from telling him where to shove his shadowing.

"Yeah," Beckett says, looking around the room. "Tell me about it. I'm still not totally convinced this isn't some elaborate prank they've roped you into, too."

Castle's daughter laughs, giving her head a shake. "I'm not complicit in their bad behavior anymore. Unless they pay me," she adds with a devious grin that leaves Kate to wonder if her writer shadow has done exactly that in this case.

"Are they?" she asks, watching mirth flood the girl's face. "Paying you, I mean."

"Beckett! You made it."

Beckett turns to find Castle striding across the living room, looking jovial.

"Yep," she says dryly. "I made it."

"Good, because otherwise Alexis and I would be eating a lot of Chinese food on our own," he cracks, making a show of slinging his arm around his daughter and dragging her into a hug.

"Correction," the girl says, her words half-muffled by her father's sweater. " _You_ would be eating a lot of Chinese food on your own. I already ate dinner."

Beckett snickers behind her hand as Castle feigns hurt.

"Well, I could always bring leftovers into the precinct, give the boys a crack at them."

Alexis shakes her head, squirming away. "Whatever you do, just don't expect me to eat it for breakfast."

Castle laughs. "Duly noted, pumpkin."

Alexis nods. "Better be. Enjoy your food, Dad. Detective," she adds, giving Kate a small smile.

Beckett returns the smile, rocking from foot to foot as the girl grabs her soda and makes her way upstairs. She sneaks a look across the countertop, studying her shadow. He's different here; same infuriating, unrepentant twist of his lips, same hint of stubble on his jaw, but he seems softer somehow, more authentic.

"So," Castle claps his hands. "Food should be here in a few minutes, but if you wanted to start looking at pictures, I pulled a few albums out. They're on the coffee table."

Right, yes. The thing she's here to do: prove her coworker isn't just messing with her and get something embarrassing to hold over Ryan's head the next time she needs ammunition. She's not here to spend time with the man her teammate had once described as smart and funny, and someone she would really like.

If he knows he just caught her staring at him, he doesn't gloat.

"Pictures are fine," she says, waiting for him to grab a bottle of water – two, she realizes as he hands one over to her – and leave the kitchen. The sooner she sees the photos, the sooner she can go home.

"Okay," he says once they've rounded the couch in the living room, "these are the photo albums for your perusing pleasure. And to sweeten the deal – as well as provide you with further proof – I've also set up the projector to show you some home movies. G-rated, of course. Unless you wanted to see the others."

"Castle," she snaps, not wanting to hear about his homemade porn, real or made up to get a rise out of her.

His grin turns impish. "Kidding, Detective. I don't keep those out where people can see them. Now, if you'd like to step into the other room…"

"I can leave," she says, watching his demeanor shift once more at her threat. The cocky smile fades from his lips and he lifts his hands in surrender.

"Sit, sit. I'll behave."

Her lips purse in amusement. Fat chance of that happening. She's certain that the man hasn't behaved a day in his life.

She sits anyway, looking expectant. "Okay, Ricky, let's see these embarrassing pictures of yours."

He brandishes a thick, worn-looking leather photo album, dropping to the cushions beside her. She waits until he's settled before she opens the cover with care, revealing infant Rick Castle's adorable gummy grin.

She's never considered herself to be a baby person, but damn if he wasn't cute back then with his chubby cheeks, tufted dark hair, and bright blue eyes. She makes sure to tell him so, watching as he preens and then pretends to be offended by her use of the past tense. Beckett just grins, turning back to the album.

The next page reveals more photos of him. She watches him grow from an infant to a toddler, and eventually to a young boy with a gap-toothed, devious smile. Some pictures feature his mother, some are of Castle alone, and eventually some begin to feature other children. A girl with ice grey eyes and blonde hair joins him first, a second darker-haired girl comes along what looks to be two or three years later, and then a sandy-haired boy with the same eager grin she recognizes from the bullpen each day.

Kevin Ryan.

Well damn. They really aren't messing with her.

Beside her, Castle sits up straighter, his too-pleased gloat coming a second later, "Told ya. Did I not tell you?"

It should rankle, the insufferable cockiness in his voice, but she can only stare at the photos. Short of this being a _really_ good Photoshop job – and there's a part of her that wouldn't put it past Castle to do that for the sake of the long con – she's looking at the proof she had demanded.

"I believe I did tell you. Yes, yes, I did," he adds, crowing in delight. God, he must be unbearable to play poker with; he probably does obnoxious victory laps after every winning hand.

"Shut up."

Thankfully, she's saved from whatever happy dance he's about to do by the insistent noise of his apartment buzzer.

"Oh, that's our food," he says, ever cheerful, hopping up from his spot beside her to scamper to the door.

Beckett allows her eyes to follow him, an amused smile slipping across her lips; he's completely ridiculous.

But damn if a traitorous part of her doesn't like that.

Castle bustles back in a moment later, already explaining at top speed what he'd ordered for them. Beckett pushes the photo album to one side, making sure it won't go spilling to the floor before facing him. She takes her food, cradling a carton of rice between her knees to free her hands for more.

"And don't worry," Castle adds once she accepts her entrée plate, "I got extra crab rangoon, just for you."

Her eyes narrow. "How did you–"

"I pay attention," he says, like it's the most obvious thing in the world. "You'll also find that I got your regular order, complete with the extra spicy duck sauce."

He – oh, he did. He got everything she likes.

Words like _generous_ and _thoughtful_ trip through her skull, sounding suspiciously like Ryan.

"Thanks," she says quickly, before she allows herself to contemplate what that could mean. She's seen Rick Castle flip the switch on and off so often in the short time he's been following her, it's hard to know which version of him is the real deal: the incorrigible flirt with a penchant for saying obnoxious things, or the man whose praises Ryan has sung more than a few times, the man who seems to have memorized her Chinese food order already.

He nods, balancing his own food with one hand as he lowers himself beside her again. The carton on top wobbles but doesn't fall, and her lips twitch.

"Smooth," she teases.

He offers her a sheepish smile. After a moment he shrugs it off, passing her a package of cutlery and a wrapped set of chopsticks.

"Pick your poison."

She takes the plastic silverware, giving the chopsticks a long glance. She's not _terrible_ with them, but her record isn't great, either. The last thing she wants is to have Castle mocking her the whole time they eat.

Her shadow doesn't seem to share her reticence; he unwraps the chopsticks and dives into his food with the gusto of a man consuming his last meal. His first few attempts go about as well as she expects, but then he gets the hang of it and she reluctantly decides to follow his lead.

"So," she says once they've dulled the ragged edges of their hunger. "What's the Christmas pageant story you promised?"

Castle laughs, wiping his mouth on a napkin. "I knew that was what got you here."

"Well, that and the mullet. Which I have yet to see in that photo album. So start talking." She motions for him to move things along, ignoring the way his grin widens.

Ass. He probably planned it this way.

"I don't know if you know this about Kevin, but he hasn't always been the outgoing, vibrant guy that he is today; he had to grow into that sparkling personality of his. When he was in the first grade, Sister Margaret Frances decided to help with that – or so she thought – by casting Kev as Joseph in the annual Christmas pageant. It was quite the honor, he even beat out half a dozen older kids with his quick ascension from a mere sheep in the flock to one of the starring roles. As you can probably imagine, Ryan was terrified, so he turned to the resident acting expert in the family: my mother."

Beckett's lips quirk as he pauses. He does have a gift for setting up a scene, doesn't he?

"Now, my mother was thrilled to finally have another actor in the family. Up until that point I'd been a bitter disappointment of untamed class clownery. So when Kevin called and blurted out a request for help, Mother pretty much cleared her schedule for the next two weeks. Which wasn't hard, because she was between both shows and husbands at that point."

She snickers, drawing her legs onto the couch between them. Her knee nudges the outside of Castle's thigh, the touch far more comfortable than she would've ever expected, but she doesn't jerk back. Better not to draw attention to it.

"Every day after school, they worked," Castle continues. "I was in charge of picking Kevin up and taking him home, so I would sit and watch them do breathing techniques, hear mother lecture about stage presence and taking command of the room, and listen to them rehearse. 'Give me the line, Darling,' she would say. Over and over, until finally Kev was able to deliver his lines without issue."

A genuine smile flirts at her lips. That's sweet. She can picture Castle's mother as the vibrant but dogged instructor and Castle as the dutiful – most likely bored – onlooker.

"I'm sensing a but coming," Kate murmurs, eager to hear more, to find out what happens next.

Her shadow laughs, twisting in his seat to face her completely. "I don't know if you've ever been to a Christmas pageant at a school like Saint Agnes, but it's kind of a big deal. They even had two shows, one for the elementary school ages, and then another for junior high and high school, and it was still a huge affair. Mother and I arrived early at Kevin's insistence, and the place was already packed. Poor Kev was backstage freaking out, insisting he couldn't do it, he wouldn't do it."

"Poor Ryan," she says, knowing that terror all too well. "Did he do it?"

"Well, Mother was able to give him one of her pep talks and psyched him up and sent him on his way. But not before he stipulated that I needed to stay in the wings, like I had when they were rehearsing."

She nods, pressing her fingers to her lips. "That's sweet."

"It was sweet of me, wasn't it?" He smirks at her rolling eyes.

"Does your ego really need this much stroking?" she asks, holding up a hand before he can reply with something dirty. She had walked into that one. "Finish the story."

Castle laughs. "As requested, I stayed in the wings while Mother took her place in the audience with my aunt, uncle, and Kevin's oldest sister, Gwen. Stacy, his other sister, was part of the choir of angels in the same production, in case you were wondering. She was in fifth or sixth grade at the time."

"Uh huh," she indulges. "What happened?"

"Well, the play started just fine. But as soon as they got to Kevin's first line, he froze. Between the pressure and the people staring up at him, the poor kid completely froze."

"Oh no," Kate chuckles. "Poor Kev."

Castle nods. "It got worse. Or better, depending on how you look at it."

"He didn't vomit, did he?"

Her shadow shakes his head. "Thankfully, Joseph did not hurl all over Mary or the first inn keeper to turn them away. Instead, he turned around, and ran off the stage in tears."

It wouldn't be funny in the least if she had been in Ryan's shoes, but Castle's delivery makes her smile. He is nothing if not a storyteller. "Poor guy. But he ran to you, didn't he?"

Castle nods. "He did. He was inconsolable. Crying, stuttering, everything. Meanwhile, Margaret Frances was beside herself, snapping at me to do something to get Kevin back out on stage and keep the pageant moving. But instead of forcing my crying cousin back on stage, I told him to take off his costume and give it to me."

Laughter bubbles from her lips. "Oh no. You didn't."

Another nod. "I did. I threw his costume on over my clothes – even though it was at least three sizes too small – and I went out there in his place."

Beckett buries her face in her shoulder, surrendering to her amusement. Oh God, that is amazing. The thought of suave, smug Richard Castle darting out in a costume meant for someone half his size…

"Of course, everyone started to laugh when they saw me – except for the nuns; they were livid – so much so that I froze at first. But the next thing I knew, my mother was calling ' _Give me the line, Darling'_ from the crowd. So I did. Then I gave the next line, and the one after that. By the time that scene was over and I walked off stage, Kevin had pulled himself together enough to take his costume back and finish the pageant."

Castle claps his hands. "And that's the story of how I got booted from a school I never even attended."

Another peal of laughter slips out. "You did not."

He grins, almost as if he's pleased she can see through his bullshit. "No, I didn't. But I'm sure they wanted to ban me after that."

Beckett shakes her head. "What you did was very sweet, Castle. Absurd, but very sweet. I don't think anyone could fault you too badly for trying to help your cousin."

"Oh," he scoffs, reaching for his drink, "you would be surprised. It's probably for the best that my mother never tried to send me there."

"One pageant was enough for you, huh Ricky?"

"Those nuns were seriously scary." He shudders.

Beckett smothers another laugh. For a man who claims he's not an actor, he has an impressive flair for drama.

 _He's smart and he's funny, Beckett. You two might really hit it off._

"You did a good thing, helping him that way," she says, ignoring the echo of Ryan's insistent words, reaching out instead to pat Castle's arm. "Even if it did come at _great_ personal expense to you."

His eyes narrow. "Are you mocking me, Beckett? After I welcomed you into my home and shared my family history with you? You mock me?"

She grins; this is far more fun than she had expected it to be. "Uh huh. Get used to it. Now give me another story, hot shot."

Despite his bellyaching, he's more than happy to oblige.

* * *

"Morning, Beckett."

Any other morning and she might not respond, or she might simply wave, but this morning Beckett lifts her head and smirks. "Morning, Joseph."

Ryan stops, the coffee mug halfway to his lips. His eyes narrow. "He did not tell you that."

"Oh, he did. Your _cousin_ was all too willing to give me the dirt."

He sputters. "I-that's so not cool."

She blinks, trying to look innocent. "What's the matter, Ryan? I thought you wanted us to get along."

"Seems to me you're getting along a little too well now," he grumbles, only to flip a switch and brighten a moment later. "How well _are_ the two of you getting along, Beckett?"

Beckett rolls her eyes. "Not as well as you're hoping, Millionaire Matchmaker. I just appreciate his recent cooperation to help embarrass you. I'm sure he'll be back to being a pain in my ass in no time."

She doesn't need to tell Ryan that the time she'd spent at Castle's loft had been surprisingly pleasant, as had the man himself. There's also no need to tell him that she's almost certain she laughed harder than she has in a long time, or that it had been a chore to unfold herself from the comfort of Castle's leather couch to leave.

And she's especially not going to tell him that she has already accepted an invitation to dinner at Castle's for the coming weekend.

To hear more stories, of course.

* * *

 _Prompt from Lou: I would love someone to write a fic in which it turns out Ryan and Castle are fairly closely related. Brothers, cousins, etc._

 _Thank you for reading! I hope you enjoyed the story!_


End file.
